Reversible-flow pump



R. MAW.

REVERSIBLE FLOW PUMP.

APPLICATION FILED FEB. 20. I917- RENEWED JUNE II. 1919. 1,330,889. Patented Feb. 17,1920.

UNITED STATES PATENT OFFICE.

ROBERT MAW, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR TO THE UNIVERSAL MACHINERY COMPANY LIMITED, OF MONTREAL, CANADA.

REVERSIBLE-snow PUMP.

Specification of Letters Patent.

Patented Feb. 1'7, 1920.

Application filed February 20,1917, Serial No. 149,826. Renewed June 11, 1919. Serial No. 303,477.

of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Reversible-Flow Pumps, of wh ch the following is a full, clear, and. exact descri tion.

T is invention relates to improvements in reversible flow pumps, and the ob ect of the invention is to provide a pump adapted to circulate a transmission liquid in either posi-' tive or reverse direction without altering the direction of revolution of the pump.

A further object is to provide a pump 1 which will circulate the liquid in either direction with equal facility and efficiency and for the reason that the oil becomes filled with air and churned to a froth. In my copending application, I have disclosed means for separating the air from the oil and elimi-- nating this froth, but the apparatus shownis intended for operation principally in one direction, as in the case of an automobile, and in spite of the air separating means would not be properly efiicient, where reversing was frequent, such as would occur if the pump were used to supply oil to a motor running a plate rolling machine or the like. The reason for this is that the separatin chamber is too large, and contains too inuc space for an air cushion, so that too much time is lost in fillin this chamber before the oil can reverse its ow as regards the utilizing device. 4

To overcome this condition, I divide the separation chamber into two parts and slightly alter the arrangement of suction, discharge and return passages from that shown in my co-pending case, with the result that the pump draws oil from one 'cham her and disc arges it into the other chamber, from wh ch it flows to the motor or other utilizing device, this chamber being kept full. The oil returned from the motor .fiows into the-chamber where the separation takes place. When the pump is reversed,

the conditions in the chambers reverse. In this way, the amount of air space is reduced, and the reversing more quickly effected. Each chamber is provided with an air outlet valve.

In the drawing which illustrate'the in ventionz- Figurel is a diagrammaticelevation of the device with part of the casing broken away.

Fig. 2 is aisection on the line 22, Fig. 1. Referring more particularl to the drawings, 11 designates a pump liaving an extension 12 of the casin divided by. a partition 13 into two entire y separate chambers 14 and 15. Passages 16, 17, 18 and 19 are provided. The assages 16 and 17 connect the pump with t e chambers 14: and 15, and the passages 18 and 19 connect the' chambers 15 and 14;, with the motor 20. When the pump is operated, it draws oil through the passage 16 from a point near the bottom of the chamber 14, and dischar I it through the passage 17 into the cham er 15. From the chamber 15, the oil flows through the [point near the bottom thereof and contiglu- 1 ous to the inlet of the passage 16. In t operation, the chamber 15 is maintained full of oil and the pressure of the oil holds'the air escape valve 22 closed. The oil level in the chamber 14 is somewhat below the to of the chamber, so that the valve 21, whic is normally open, permits air separating from the oil to escape. When the pump is operated to reverse the flow of oil, it draws oil from the chamber 15 through the passage 17, and discharges it into the chamber 14 through the passage 16. This discharge of oil almost instantly fills the chamber 14 and closes the valve 21, the oil thus accumulated being drawn from the chamber 15, so that The great advanta e of this arrangement is that. the volume 0 air space is reduced, and on whichever side the pressure exists, the chamber is completely filled with purely li 'uid oil.

aving thus described my invention, what I claim is 1. In a device of the'character described, the combination with a pump and a motor, of an oil receptacle divided into two isolated chambers, a passage from each chamber connected to the pump and a passage from each chamber connected to the motor.

2. In a device of the character described, the combination with ap-ump and a motor, of a receptacle intermediate the pump and motor divided into two isolated cham-' hers, a passage leading from near the bottom of each chamber to the pump, and a passage leading from near the bottom of each chamber to the motor, and a normally open valve in each chamber closable by accumulation of oil in the chamber.

3. In a fluid transmission system, a pump and a motor, a transmission fluid receptacle intermediate the pum and motor divided into two isolated cham ers, a normall open air vent in each chamber, means w ereby the pump will draw liquid from one chamber and completely fill the other chamber closing the valve thereof, and means where by oil forced into said second chamber will flow to the motor and return from the motor .to the first chamber.

ROBERT MAW. 

